(Field Test on Sand)
1.Take a glass of water and add some quantity of sand in it. Then shake it vigorously and allow it to settle. If clay is present in sand, it will form a distinct layer at the top of sand.
2. In order to detect presence of organic impurities in sand, add sand to the solution of sodium hydroxide or caustic soda and then stir it. If colour of solution changes to brown, it indicates the presence of organic impurities.
3.Take a pinch of sand and taste it. If tasted salty then there exist some salt in sand.
4. Take sand and rub it against the fingers. If fingers are stained, it indicates that sand contains earthy matter.
5. The colour of sand will indicate the purity of sand. The size and sharpness of grains may be examined by touching and observing visually.